Fluidically controlled refill mechanism with backflow preventer

ABSTRACT

A refill mechanism, for example, a water closet tank refill apparatus is provided with a fluidically controlled valve which maintains itself in the &#39;&#39;&#39;&#39;on&#39;&#39;&#39;&#39; position once the fluid flow starts and switches to the &#39;&#39;&#39;&#39;off&#39;&#39;&#39;&#39; position in response to the attainment of a predetermined liquid level. The flowing fluid in the control chamber of the mechanism, acts as a wall or air barrier. When the fluid flow stops, the barrier is eliminated leaving a substantial distance between the maximum water height and the lowest &#39;&#39;&#39;&#39;siphon&#39;&#39;&#39;&#39; inlet to the valve, thereby preventing accidental backflow of water from the tank into the main waterline.

United States Patent {72] Inventors Barry S. Fichter Dunellen; Edward H.Bell, Clinton, both of, NJ. [21] Appl. No. 34,679 [22] Filed May 5,1970{45] Patented Sept. 7, 1971 [73] Assignee American Standard Inc.

New York, NY.

[54] FlLlJllDllCALLY CONTROLLED REFILL MECHANISM Wll'llll BACKFLOWPREVENTER 9 Claims, 5 Drawing Figs.

[52] US. Cl 137/815 [51] lnt.Cl 1815c 3/04 (50] Field ofSearch 137/815;235/201 PF [56] References Cited UNlTED STATES PATENTS 3,262,468 7/1966Metzger 137/815 X 3,386,709 6/1968 Drayer 137/81.5 X

Primary ExaminerSamuel Scott Attorneys-Sheldon 11. Parker and Tennes 1.Erstad ABSTRACT: A refill mechanism, for example, a water closet tankrefill apparatus is provided with a fluidically controlled valve whichmaintains itself in the fon position once the fluid flow starts andswitches to the off position in response to the attainment of apredetermined liquid level. The flowing fluid in the control chamber ofthe mechanism, acts as a wall or air barrier. When the fluid flow stops,the barrier is eliminated leaving a substantial distance between themaximum water height and the lowest siphon" inlet to the valve, therebypreventing accidental backflow of water from the tank into the mainwaterline.

(OFF) PATENTED SEP 7 I971 FIG 2 (REFILL) F IGJ FF) FIG.4

FIG.3 (SHUTOFF) INVENTORS Barry $.Fich1er EdwabH. Bell ATTORNEYFLUIDICALILY CONTROLLED REFILL MECHANISM WITH BACKFLOW PREVENTERBACKGROUND OF THE INVENTION Related Patent Applications The invention isdesigned for use with a fluidic valve of the type disclosed and claimedin copending U.S. Pat. application, Ser. No. 34,780, filed May 5, 1970,in the name of Barry S. Fichter, and entitled: Pilot Valve OperatedFluidic Valve Field of the Invention This invention relates to a fluidicvalve mechanism having a backflow preventer, and more particularly, to afluidic water closet refill valve mechanism having a backflow preventerin corporated in the liquid-level-sensing portion of the valvemechanism.

Description of the Prior Art The need for an inexpensive, efficient,reliable refill valve, for a varietypf applications has long existed. Atypical example is found in the case of water closet refill devices.These devices are characteristically noisy, are excessively subject towear and do not stay in the full open position during the entire fillingoperation. They typically begin a slow close procedure well before thetank is filled with water to the desired level.

Furthermore, these valves require the use of a large float and lever armmechanism and are relatively expensive.

A further problem is that leakage of any sort from the tank causes thewater control valve to open, thus replenishing the water due to leakage.A permanent on" situation is thus produced, resulting in flooding or thelike.

It has been proposed to use fluidic valves in order to overcome theaforementioned problems. It is necessary, however, that the water levelin the tank be precluded from accidentally attaining a level which is ashigh as or higher than any of the valve ports. Unfortunately, thebackflow prevention mechanisms normally employed in combination withwater closet refill mechanisms are not suitable for use with fluidicvalves which respond to the attainment of a predetermined water level inthe tank.

SUMMARY OF THE INVENTION It has now been found that a refill mechanismusing a fluidic valve which responds to the attainment of apredetermined level by the water, can be provided with a simple,reliable and positive backflow preventer.

This is achieved by having an outlet conduit from the valve incommunication with an upper region of a chamber which serves as a liquidlevel sensor and backflow preventer. The control port of the fluidicvalve is in communication with a region of the chamber which is belowthe aforenoted upper region. The chamber has an air inlet opening at alevel which is equal to the height to be attained by the water in thetank.

The chamber also has an elongated vertical opening which is positionedand dimensioned with respect to the outlet conduit from the valve suchthat water flowing from the outlet conduit substantially completelycloses the vertical opening. The only source of air for the control partof the fluidic valve is through the air inlet opening of the chamber.

When the water in the tank reaches a predetermined level, the air inletopening of the chamber is blocked and the switching action of thefluidic valve is activated, thereby shutting off the valve and stoppingthe waterflow. Therefore, the vertical opening in the chamber is openand an airgap is produced between the region of the chamber which is incommunication with the control port of the fluidic valve and the waterin the tank. Thus, a negative pressure in the main waterline whichsupplies water to the tank through the fluidic valve, cannot siphonwater from the tank into the main waterline.

BRIEF DESCRIPTION OF THE DRAWINGS The objects, features and advantagesof the present invention will be fully understood as the descriptionofthe invention proceeds, particularly when taken together with theaccompanying drawings wherein like reference numerals indicate similarparts throughout the several drawings, and wherein:

FIG. I is an elevation view, partly in cross section, ofa refillmechanism in accordance with the present invention, said mechanism beingin the of position;

FIG. 2 shows the mechanism of FIG. ii, in the refill position;

FIG. 3, shows the liquid level sensor and backflow preventer chamberduring the shutoff" operation;

FIG. 4 is another side view of the liquid level sensor and backflowpreventer chamber of FIG. 3; and

FIG. 5, is a bottom view of the liquid level sensor and backflowpreventer chamber.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. I, the fluidicrefill mechanism is in the of position when the diaphragm 12 has agreater fluid pres sure exerted on the pilot valve side 13, of thediaphragm I2, than on the sealing side 11, of the diaphragm. When thepilot valve 14 is opened, by moving the diaphragm I6 away from the seat18, the fluid pressure on the pilot valve side 13, of the diaphragm 12,is released and the fluid pressure on the sealing side ll, of thediaphragm forces the diaphragm away from the seat 117.

Water then flows from the fluidic valve into the water tank (not shown)by means of a main refill conduit 20, and into the rim of the bowl (notshown) by means of a secondary conduit 22. The secondary conduit 22provides communication between the fluid valve outlet 24, and an inlet25 to the liquidlevel-sensing and backflow preventer chamber 26.

The control port 30, of the fluidic valve, is in communica tion withoutlet port 32, in the chamber 26. The outlet port is positioned justbelow the inlet port 25, and is advantageously provided with anextension tube 33, which has a diagonally slanted opening proximate theinlet port 25.

During the refill operation, water flowing from the water inlet port 25,seals the vertical, extended opening 40, in the sidewall 42, of thechamber 26.

It is apparent that the elongated vertical opening 40, must be properlydimensional and positioned, such that the waterflow from the water inletport 25, completely closes the vertical opening.

Air is drawn into the chamber 26, through the bottom air inlet 44, intothe outlet port 32 and into the control port 30, of the fluidic valve.

When the level of the water in the tank reaches the air inlet port 44,which is in effect, at the bottom of the backflow preventer chamber 26,air is precluded from flowing into the air outlet port 32.

The water jet from the water inlet port 25 is normally confined betweenthe sidewalls 50 and SI, of the chamber 26, forming a curtain of water.

However, as shown in FIG. 3, the closing off of the air inlet 44,results in a vacuum in the conduit 36, between the sensing or controlport and the air inlet port 32, causing the water jet from the waterinlet 25 to be pulled toward the tube 33.

. The water fills the tube 33, which is functioning as a sensing tube,and flows to the sensing or control port 30. The power jet of waterentering the fluidic valve through the conduit 21, is caused to flipover from its flow along wall 23, to a flow among the opposite wall 27.

This results in the power jet of water to enter the conduit 29, therebyclosing the fluid valve.

It should be noted that a more detailed description of the operation ofthe fluidic valve can be found in the related copcnding U.S. Pat.application, Ser. No. 34,780, filed May 5, I970.

With the valve closed, thejet of water from the inlet port 25 ceases toflow leaving the sensing tube 33, open to the air at a height H abovethe overflow tube 28, and by an additional distance h, which is thedistance between the bottom of the chamber 26, on the top of theoverflow tube 28.

The water level in the tank will normally be equal to the height of thebottom of the chamber 26, but in any event, cannot be above the top ofthe overflow tube 28, which is in communication with the bowl of thetoilet. Thus water in the tank will never reach the height of thesensing tube 33, and cannot be drawn into the main conduit 53.

It should be noted that although the sensing tube draws in water ratherthan air, when the water level in the tank reaches a predeterminedlevel, the tube is always filled by fluid from the jet leaving the waterinlet port 25 and never by water from the tank (not shown).

Obviously, many modifications and variations of the present inventionare possible in the light of the above teaching. It is, therefore, to beunderstood that the invention may be practiced otherwise than asspecifically described herein.

I claim:

1. A water closet refill mechanism having a fluidic valve and a backflowpreventer, comprising:

A. a fluidic valve, said fluidic valve having a control port and beingautomatically closed in response to the termination of air beingaspirated through said control port into said fluidic valve; and

B. a backflow preventer and liquid-level-sensing chamber,

said sensing chamber having a water inlet in an upper region, means forproviding communication between said control port of said fluidic valveand a region of said chamber which is below said upper region, an airinlet in a lower region of said chamber, and a backflow preventer portat least intermediate said upper region and said lower region,communicating with said control port, said water inlet and said backflowpreventer port being relatively positioned such that water flowing intosaid chamber through said water inlet forms a curtain across saidbackflow preventer port.

2. The structure of claim 1, wherein said backflow preventer port is anelongated, vertically extending port.

3. The structure of claim 1, wherein said backflow preventer andliquid-level-sensing chamber has an open bottom end, said open bottomend being said air inlet.

4. The structure of claim 1, wherein said backflow preventer andliquid-level-sensing chamber is provided with a conduit which extendsthrough a first wall of said chamber to a point proximate said waterinlet, said conduit being at least part of said means for providingcommunication between said control port of said fluidic valve and saidregion of said chamber which is below said upper region.

5. The structure of claim 1, wherein said water inlet supplies water toa region intermediate two opposite walls of said backflow preventer andliquid-level-sensing chamber, said two opposite walls being spaced aparta distance such that water from said water inlet substantiallycompletely fills a vertically extending region between said two walls,said region being intermediate said backflow preventer andliquid-level-sensing chamber which is in communication with said controlport of said fluidic valve.

6. The structure of claim 5, wherein said backflow preventer andliquid-level-sensing chamber is provided with a vertically extendingslot in each of said two opposite walls, the slots serving as means formounting said backflow preventer and liquid-levcl-sensing chamber on awater closet overflow tube.

7. The structure of claim 6, wherein said slots are positioned such thatthe region between said slots and another wall of said backflowpreventer and liquid-levcl-sensing chamber constitutes said air inlet.

8. The structure of claim 7, wherein said backflow preventer andliquid-level-sensing chamber is provided with a conduit which extendsthrough said another wall of said chamber to a point proximate saidwater inlet, said conduit being at least part of said means forproviding communication between said control port of said fluidic valveand said region of said chamber which is below said upper region.

9. The structure of claim 8, wherein said slots are located in avertically extending plane which is substantially intermediate of saidwater inlet and said air inlet.

1. A water closet refill mechanism having a fluidic valve and a backflowpreventer, comprising: A. a fluidic valve, said fluidic valve having acontrol port and being automatically closed in response to thetermination of air being aspirated through said control port into saidfluidic valve; and B. a backflow preventer and liquid-level-sensingchamber, said sensing chamber having a water inlet in an upper region,means for providing communication between said control port of saidfluidic valve and a region of said chamber which is below said upperregion, an air inlet in a lower region of said chamber, and a backflowpreventer port at least intermediate said upper region and said lowerregion, communicating with said control port, said water inlet and saidbackflow preventer port being relatively positioned such that waterflowing into said chamber through said water inlet forms a curtainacross said backflow preventer port.
 2. The structure of claim 1,wherein said backflow preventer port is an elongated, verticallyextending port.
 3. The structure of claim 1, wherein said backflowpreventer and liquid-level-sensing chamber has an open bottom end, saidopen bottom end being said air inlet.
 4. The structure of claim 1,wherein said backflow preventer and liquid-level-sensing chamber isprovided with a conduit which extends through a first wall of saidchamber to a point proximate said water inlet, said conduit being atleast part of said means for providing communication between saidcontrol port of said fluidic valve and said region of said chamber whichis below said upper region.
 5. The structure of claim 1, wherein saidwater inlet supplies water to a region intermediate two opposite wallsof said backflow preventer and liquid-level-sensing chamber, said twoopposite walls being spaced apart a distance such that water from saidwater inlet substantially completely fills a vertically extending regionbetween said two walls, said rEgion being intermediate said backflowpreventer and liquid-level-sensing chamber which is in communicationwith said control port of said fluidic valve.
 6. The structure of claim5, wherein said backflow preventer and liquid-level-sensing chamber isprovided with a vertically extending slot in each of said two oppositewalls, the slots serving as means for mounting said backflow preventerand liquid-level-sensing chamber on a water closet overflow tube.
 7. Thestructure of claim 6, wherein said slots are positioned such that theregion between said slots and another wall of said backflow preventerand liquid-level-sensing chamber constitutes said air inlet.
 8. Thestructure of claim 7, wherein said backflow preventer andliquid-level-sensing chamber is provided with a conduit which extendsthrough said another wall of said chamber to a point proximate saidwater inlet, said conduit being at least part of said means forproviding communication between said control port of said fluidic valveand said region of said chamber which is below said upper region.
 9. Thestructure of claim 8, wherein said slots are located in a verticallyextending plane which is substantially intermediate of said water inletand said air inlet.